1. Field
Embodiments of the invention relate to the field of networking, and more specifically to the power management of network elements.
2. Background
A network element (e.g., a router, switch, bridge, etc.) is a piece of networking equipment, including hardware and software that communicatively interconnects other equipment on the network (e.g., other network elements, computer end stations, etc.). Network elements typically include one or more networking cards (e.g., one or more control cards, one or more line cards, one or more service cards, etc.) inserted into a chassis. For example, many network elements include an active control card and a synchronized standby control card to provide redundancy. The control cards perform signaling, routing (including creation of and/or management of routing tables), bridging (including creation of and/or management of bridging tables), connection setup, session setup, etc. The line cards handle packet processing including forwarding and/or switching at high speed.
A network element has a limited power capacity and each networking card may require a different amount of power. For example, a quad processing core control card requires more power than a dual processing core control card. The network element may overheat causing electrical equipment to melt and/or may potentially cause a fire if the power capacity is exceeded.
Some network elements require a power consumption value to be programmed (e.g., in an EEPROM) in the networking cards. When the networking card is inserted into the chassis, the power consumption value is read. If the network element determines that sufficient power is available the networking card is powered up. However, if the network element determines that there is not sufficient power (e.g., the power capacity would be exceeded if this card is powered up), the networking card is denied power which disables the networking card. If the power capacity decreases, the network element powers down networking cards in descending order, starting with the highest number slot of the chassis. If the power capacity is increased, the powered down networking cards are brought back up.